道路有机硅密封胶的性能评价与技术要求

为了评价道路有机硅密封胶的性能,分析了国内外的各种技术标准,根据路用性能要求,提出了表干时间、固化时间、流平性、流值、弹性(复原)率以及低温拉伸这6个评价指标.分别对4种有机硅密封胶(2种进口材料和2种国产材料)进行试验,试验证实这些材料均为自流平材料,表干时间不超过90 min,固化时间为2～3周,弹性(复原)率均超过90％,90℃流值均为0 mm,-30℃下至少可通过100％拉伸量的3次循环.结果表明:有机硅密封胶是高弹性材料,具有开放交通快、施工方便等优点,且具有优越的高低温性能.另外还根据试验结果提出了相应的技术要求.     

浅析城市风貌特色塑造

通过对瑞安城市中心区概念城市设计国际竞赛的总结,探索中心区城市设计策略,以挖掘城市资源禀赋,塑造城市风貌特色,从而改变城市建设"千城一面"的趋同化现象。     

浅析高层建筑给排水消防设计

高层建筑消防给排水施工设计所涉及的专业内容较为广泛,需要结合每个系统的实际情况展开最具安全保障的有效设计,强化设计的稳定可靠性。唯有在可靠的技术保障下实施便捷操作,方能保证建筑与人员的安全。     

谈波尔多住宅--从“异规”到“触底”

本文从塞西尔·巴尔蒙德的著作《异规》出发,阐述了波尔多住宅的结构形式,分析了库哈斯与巴尔蒙德在合作波尔多住宅的建构思路,并挖掘了波尔多住宅建构形式的成因,以求回归到建筑空间的本质,为建筑形式问题的探索尝试一种思路。     

一种常见电梯鼓式制动器的性能改进及其检验

制动器是电梯重要的安全部件,一旦失效,可能造成轿厢蹴底、冲顶、开门运行以致人员受到剪切伤害等严重后果。所以,电梯的制动系统除了电气制动外,还应有一个机一电式摩擦型的制动器,其兼备了驻车制动和行车紧急制动的功能。     

谈某商住楼基坑支护施工技术

结合具体工程实例,对商住楼基坑土方开挖要点进行了阐述,并对放坡喷锚及框格梁施工工艺流程进行了详细介绍,指出建筑深基坑的开挖与支护结构是一个系统工程,要选择合理的施工方案,严把质量关,以确保工程的顺利进行。     

对给排水工程投资经济分析的几点看法

为了使市政给排水工程投资分析更切合实际,分别就成本分析表、损益表、现金流量表及敏感性分析中易出现的问题提出了自己的看法,并对表中部分内容作了调整。     

Quantitative study of the effect of electromagnetic field on scale deposition on nanofiltration membranes via UTDR

Ultrasonic time-domain reflectometry (UTDR) as an in situ, non-invasive real-time technique has been successfully utilized to quantify membrane fouling and cleaning. This study describes an existing ultrasonic technique for quantitative study of the effect of magnetic fields on CaCO₃ scale deposition on the membrane surface during crossflow nanofiltration (NF). The fouling experiments were conducted with CaCO₃ solution containing Ca²⁺ of 1.8 and 3 mmol/L. The experimental electromagnetic field (EMF) was 0.02 T. A commercial NF membrane and a highly sensitive ultrasonic sensor were used in all the experiments. Results show a good relationship between the ultrasonic measurements and the development of CaCO₃ scale on the NF membrane surface. An increase in the amplitude of differential signal with operation time results from the deposition of the CaCO₃ scale layer. In addition, the movement of the differential signal in the time domain observed is associated with an increase in the thickness of the fouling layer. The UTDR technique is capable of measuring the rate of fouling layer formation under different treatment conditions, i.e. with non-magnetic field (NMF) and EMF. Scale layer of deposited CaCO₃ obtained in the experiment with NMF is denser and thicker than that with EMF. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses imply that the magnetic treatment suppresses the formation of calcite crystals and prefers vaterite and aragonite. Furthermore, the ultrasonic technique is sensitive to the different fouling rate between experiments carried out with 1.8 and 3 mmol/L CaCO₃ solutions. The thickness of the fouling layer measured by weight measurement is consistent with that obtained by UTDR in real time. The thinner and less dense scale layer is the main reason for the slower flux decline. Overall, independent measurements such as the flux-decline data, SEM analysis and weight measurement corroborate the ultrasonic measurements.     

地下室设计技术措施探讨

从施工图审查的角度结合地下室设计常见的技术措施围绕抗浮设计、人防设计、节能设计三个大的方面进行阐述，在基础底板、侧墙、项板等技术控制方面和广大技术人员进行探讨，并在此基础上提出一些新问题。     

弹条扣件的发展及高速铁路的扣件选择

阐述了高速铁路扣件性能要求以及各型弹条扣件的特性，对现有各扣件绝缘性能进行了比选，并对我国高速铁路有碴轨道扣件的选择提出了建议，以促进我国各型弹条扣件的发展。